TWI668241B - Resist composition and patterning process - Google Patents

Abstract

The invention provides a photoresist material which is a high-sensitivity photoresist material and a negative photoresist material and has a small LWR and CDU, and a pattern forming method using the photoresist material. A photoresist material includes a polymer containing a repeating unit represented by the following formula (a1) or (a2).

Description

Photoresist material and pattern forming method

The present invention relates to a photoresist material and a pattern forming method.

With the high integration and high speed of LSI, the miniaturization of pattern rules has rapidly progressed. In particular, the expansion of the flash memory market and the increase in memory capacity are driving miniaturization. As far as the most advanced miniaturization technology is concerned, the mass production of devices using ArF lithography at the 65nm node is already underway, and the next generation of ArF immersion lithography at 45nm node is in preparation for mass production. For the next generation of 32nm node, a liquid with a higher refractive index than water is combined with a high-refractive index lens and a high-refractive index photoresist material to make use of the ultra-high NA lens for immersion lithography, with a wavelength of 13.5nm. Extreme ultraviolet (EUV) lithography, ArF lithography double exposure (double patterned lithography), etc. are candidates and have been studied.

As the miniaturization progresses and the diffraction limit of the light is approached, the contrast of the light decreases. Due to the decrease in the contrast of light, a decrease in the resolution of the hole pattern, the trench pattern, and the focus latitude in the positive photoresist film occurs.

With the miniaturization of patterns, the edge roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns are considered issues. The concentration of the base polymer and the acid generator, the effect of aggregation, and the effect of acid diffusion have been criticized. In addition, the LWR tends to increase as the thickness of the photoresist film becomes thinner, and the degradation of the LWR due to the thinning of the photoresist film becomes a serious problem.

EUV photoresist materials need to achieve high sensitivity, high resolution, and low LWR at the same time. If the acid diffusion distance is shortened, LWR is reduced but sensitivity is low. For example, by lowering the post-exposure baking (PEB) temperature, the LWR is reduced, but the sensitivity is low. Even if the amount of quencher is increased, the LWR is reduced but the sensitivity is low. The trade-off between sensitivity and LWR must be broken.

In order to suppress acid diffusion, a photoresist compound containing a repeating unit derived from an onium salt of a sulfonic acid having a polymerizable unsaturated bond has been proposed (Patent Document 1). Such a so-called polymer-bonded acid generator has a characteristic of very short acid diffusion because a polymer-type sulfonic acid is generated by exposure. In addition, sensitivity can be improved by increasing the ratio of the acid generator. The addition type acid generator also has a high sensitivity if the amount of addition is increased, but in this case, the acid diffusion distance will also increase. The acid diffuses unevenly, so if the acid diffusion increases, LWR and CDU deteriorate. It can be said that for the balance of sensitivity, LWR, and CDU, polymer-based acid generators have high capabilities. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4425776

[Questions to be Solved by the Invention]

It is hoped to develop a photoresist material in the chemically amplified photoresist material using an acid as a catalyst, which has higher sensitivity and can improve the LWR of the wire and the CDU of the hole.

In view of the foregoing, the present invention aims to provide a photoresist material in which both the positive type photoresist material and the negative type photoresist material are highly sensitive and the LWR and CDU are small, and a pattern forming method using the material. [Solution to the problem]

The inventors of the present invention have made intensive studies in order to achieve the foregoing object, and as a result, they have found that by using the polymer-bonded acid generator as a polymer-bonded acid generator, the polymer-containing unsaturated bond is contained and the polymerizable unsaturated bond is linked to fluorosulfonic acid. Part of the polymer having a repeating unit of a sulfonium salt or a sulfonium salt of an iodine atom can obtain a photoresist material with high sensitivity, small LWR and CDU, high contrast, excellent resolvability, and wide processing tolerance, and completed the present invention.

Therefore, the present invention provides the following photoresist materials and pattern forming methods. 1. A photoresist material comprising a polymer containing a repeating unit represented by the following formula (a1) or (a2); In the formula, R ^A is a hydrogen atom or a methyl group; X ¹ is a single bond or an ester group; X ² is a linear, branched, or cyclic alkyl group having 1 to 12 carbons, or 6 to 10 carbons It may be substituted with an aryl group, and a part of the methylene group constituting the alkylene group may be substituted with an ether group, an ester group, or a group containing a lactone ring, and at least one hydrogen atom contained in X ² is substituted with an iodine atom. ; X ³ is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and a part of the methylene group constituting the alkylene group may also be replaced by Ether group or ester group; Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group; and Rf ¹ and Rf ² may be combined And carbonyl groups are formed; R ¹ to R ⁵ are each independently a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched or cyclic alkyl group having 2 to 12 carbon atoms , Straight chain, branched or cyclic alkynyl group with 2 to 12 carbon atoms, aryl group with 6 to 20 carbon atoms, aralkyl group with 7 to 12 carbon atoms, or aryloxyalkane with 7 to 12 carbon atoms And some or all of the hydrogen atoms of these groups may be substituted with hydroxyl, carboxyl , Halogen atom, pendant oxygen group, cyano group, amido group, nitro group, sultone group, fluorenyl group or sulfonium salt-containing group, a part of the methylene group constituting these groups may also be substituted with ether group, ester Group, carbonyl group, carbonate group or sulfonate group; and R ¹ and R ² may be bonded together with the sulfur atom to which they are bonded to form a ring. 2. The photoresist material according to 1., wherein each of the repeating units represented by the formulae (a1) and (a2) is represented by the following formulae (a1-1) and (a2-1); ^{Wherein, R A, R 1 ~ R} 5, Rf 1 ~ Rf 4 and X ¹ are as previously defined; R ⁶ is a linear, branched or cyclic other than the alkyl group having 1 to 4 carbon atoms, the iodine Halogen atom, hydroxyl group, straight chain, branched or cyclic alkoxy group with 1 to 4 carbon atoms, or straight chain, branched or cyclic alkoxy carbonyl group with 2 to 5 carbon atoms; m is 1 Integer of ~ 4; n is an integer of 0 ~ 3. 3. The photoresist material such as 1. or 2. contains organic solvents. 4. The photoresist material according to any one of 1. to 3., wherein the polymer further comprises a repeating unit represented by the following formula (b1) or (b2); [Chem. 3] In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, a phenylene group or a naphthyl group, or a carbon number of 1 to 12 containing at least one selected from an ester group and a lactone ring. A linking group; Y ² is a single bond or an ester group; R ¹¹ and R ¹² are each independently an acid labile group; R ¹³ is a halogen atom, a trifluoromethyl group, a cyano group, a linear, branched, or cyclic group Alkyl or alkoxy having 1 to 6 carbons, or straight, branched, or cyclic fluorenyl, alkoxy, or alkoxycarbonyl having 2 to 7 carbons; R ¹⁴ is a single bond, or A linear or branched alkylene group having 1 to 6 carbon atoms, and a part of its carbon atom may be substituted with an ether group or an ester group; p is 1 or 2; q is an integer of 0 to 4. 5. The photoresist material as in 4. is a chemically amplified positive photoresist material that contains a dissolution inhibitor. 6. The photoresist material according to any one of 1. to 3., wherein the polymer does not contain an acid-labile group. 7. The photoresist material as in 6. is a chemically amplified negative photoresist material that contains a cross-linking agent. 8. The photoresist material according to any one of 1. to 7, further containing a surfactant. 9. A pattern forming method, comprising the steps of: coating a photoresist material according to any of 1. to 8. on a substrate, and performing a heat treatment to form a photoresist film; and performing the photoresist film with high energy rays Exposing; and developing the exposed photoresist film using a developing solution. 10. The pattern forming method according to 9., wherein the high-energy radiation is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm. 11. The pattern forming method according to 9., wherein the high-energy rays are electron beams or extreme ultraviolet rays having a wavelength of 3 to 15 nm. [Effect of the invention]

A photoresist film containing a polymer derived from a polymer having an unsaturated bond and having a repeating unit of a sulfonium salt or a sulfonium salt of an iodine atom at the linking portion of the polymerizable unsaturated bond with fluorosulfonic acid, because the atomic weight of iodine is large, It is characterized by a small acid diffusion. This can prevent a decrease in resolution due to the blurring of acid diffusion, and can reduce the LWR and CDU. Furthermore, the absorption of iodine by EUV with a wavelength of 13.5 nm is very large, so secondary electrons are generated from iodine during exposure and the sensitivity is high. In this way, a highly sensitive photoresist material with improved LWR and CDU can be constructed.

[Photoresistive material] The photoresistive material of the present invention contains a polymer-bonded acid generator, and specifically contains a polymer-derived unsaturated bond, and the polymer unsaturated bond has Polymers of phosphonium salts of iodine atoms or repeating units of phosphonium salts. To the photoresist material of the present invention, an acid generator different from this to generate a sulfonic acid, amidinic acid, or a methylated acid may be added.

If the polymer-bonded acid generator of the present invention is irradiated with light in a state of being mixed with a sulfonic acid and a phosphonium salt of a carboxylic acid which generate a weaker acid, a fluorinated sulfonic acid polymer containing iodine in a connecting portion, and It is more weak acid sulfonic acid and carboxylic acid. The acid generator does not completely decompose, so undecomposed sulfonium salts may exist nearby. Here, if the polymer-type fluorosulfonic acid containing iodine in the linking portion coexists with the weak acid sulfonic acid and the sulfonium salt of a carboxylic acid, the polymer-type fluorosulfonic acid containing iodine and the weak acid sulfonic acid and carboxylic acid in the linking portion will occur. Ion exchange between the sulfonium salts of acids produces sulfonium salts and sulfonium salts of polymer-type fluorosulfonic acid containing iodine, and releases weak sulfonic acids and carboxylic acids. The reason is that the polymer-type fluorosulfonate containing iodine having a high strength in terms of acid is more stable. On the other hand, even if a phosphonium salt of a polymer-type fluorosulfonic acid containing iodine in a linking portion and a weak acid sulfonic acid or carboxylic acid are present, ion exchange does not occur. The ion exchange caused by this acid-strength sequence is not only the case of phosphonium salts, but also the case of phosphonium salts. When combined with an acid generator of fluorosulfonic acid, the phosphonium salt and phosphonium salt of a weak acid act as a quencher. In addition, because iodine has a very large absorption of EUV at a wavelength of 13.5 nm, secondary electrons are generated during exposure, and decomposition of the secondary electrons is promoted due to movement of the energy of the secondary electrons to the acid generator, thereby increasing sensitivity. The polymer-bonded acid generator of the present invention can achieve low acid diffusion and high sensitivity.

For better LWR, it is effective to suppress aggregation of polymers and acid generators. In order to suppress aggregation of the polymer, it is effective to reduce the difference between hydrophobicity and hydrophilicity, reduce the glass transition point (Tg), and decrease the molecular weight of the polymer. Specifically, it is effective to reduce the polar difference between a hydrophobic acid-labile group and a hydrophilic adhesive group, and to reduce Tg by using a tight adhesive group such as a monocyclic lactone. In order to suppress the aggregation of the acid generator, it is effective to introduce a substituent or the like into the cation part of triphenylphosphonium. In particular, for a methacrylate polymer for ArF formed by an alicyclic protecting group and an adhesive group of a lactone, triphenylsulfonium formed only of an aromatic group is a heterostructure, and compatibility is low. Regarding the substituent introduced into triphenylphosphonium, it may be considered that the user has the same alicyclic group or lactone as the user in the base polymer. The phosphonium salt is hydrophilic, so when a lactone is introduced, the hydrophilicity becomes too high and the compatibility with the polymer decreases, which will cause the phosphonium salt to agglomerate. The introduction of a hydrophobic alkyl group can make the phosphonium salt uniformly dispersed in the photoresist film. In International Publication No. 2011/048919, a method is proposed in which an alkyl group is introduced into a sulfonium sulfinimidic acid sulfonium salt having an α-position fluorinated to increase LWR.

The polymer-bonded acid generator used in the present invention has not only an anion moiety bonded to the polymer main chain, but also introduced iodine with a large atomic weight, so the diffusion is small, and the acid generation efficiency is high due to the high absorption of iodine atoms. The acid generator is mixed at the monomer stage before the polymer is polymerized, so the acid generator will be uniformly dispersed in the polymer, which can make LWR and CDU better.

The improvement effect of the LWR and CDU caused by the polymer-bonded acid generator used in the present invention is effective in the formation of positive patterns, the formation of negative patterns, and the formation of negative patterns in the development of organic solvents.

[Polymer-bonded acid generator] The polymer-bonded acid generator used in the present invention, specifically, contains a polymerizable unsaturated bond and a linking portion between the polymerizable unsaturated bond and fluorosulfonic acid. A polymer having a repeating unit of a sulfonium salt or a sulfonium salt of an iodine atom, which contains a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (also referred to below as Repeat unit a2). [Chemical 4]

In the formula, R ^A is a hydrogen atom or a methyl group. X ¹ is a single bond or an ester group. X ² is a linear, branched or cyclic extension of 1 to 12 carbon atoms of alkyl group, or an arylene group having a carbon number of 6 to 10, and constitute a part of the alkylene group of the alkylene may be substituted with methyl groups An ether group, an ester group or a lactone ring-containing group, and at least one hydrogen atom contained in X ² is substituted with an iodine atom. X ³ is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and a part of the methylene group constituting the alkylene group may be substituted with an ether Or ester. Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of them is a fluorine atom or a trifluoromethyl group. Rf ¹ and Rf ² may be combined to form a carbonyl group. R ¹ to R ⁵ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbons, a linear, branched, or cyclic alkyl group having 2 to 12 carbons, or linear , Branched or cyclic alkynyl having 2 to 12 carbons, aryl having 6 to 20 carbons, aralkyl having 7 to 12 carbons, or aryloxyalkyl having 7 to 12 carbons, and the Some or all of the hydrogen atoms of the equivalent group may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, a pendant oxygen group, a cyano group, a fluorenylamino group, a nitro group, a sultone group, a fluorenyl group, or a sulfonium-containing group, and constitute A part of the methylene group of these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate group. Further, R ¹ and R ² may be bonded to form a ring together with the sulfur atom to which they are bonded.

It is preferred that the repeating units a1 and a2 are each represented by the following formulae (a1-1) and (a2-1). [Chemical 5]

In the formula, R ^A , R ¹ to R ⁵ , Rf ¹ to Rf ⁴ and X ^{1 are the} same as described above. R ⁶ is a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, a halogen atom other than iodine, a hydroxyl group, a linear, branched or cyclic alkoxy group having 1 to 4 carbon atoms, Or a linear, branched or cyclic alkoxycarbonyl group with 2 to 5 carbon atoms. m is an integer from 1 to 4. n is an integer from 0 to 3.

Examples of the anionic part of the monomer to which the repeating unit a1 or a2 is given include, but are not limited to, the following.

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10]

[Chemical 11]

[Chemical 12]

Examples of the cationic portion of the repeating unit a1 include, but are not limited to, the following.

[Chemical 13]

[Chemical 14]

[Chemical 15]

[Chemical 16]

[Chem. 17]

[Chemical 18]

[Chemical 19]

[Chemical 20]

[Chemical 21]

[Chemical 22]

[Chemical 23]

Examples of the cationic portion of the repeating unit a2 include, but are not limited to, the following.

[Chemical 24]

The monomer to which the repeating unit a1 or a2 is given can be synthesized, for example, in the same manner as the phosphonium salt having a polymerizable anion described in Japanese Patent No. 5201363.

The aforementioned polymer-bonded acid generator can also function as a base polymer. At this time, the aforementioned polymer-bonded acid generator contains a repeating unit having an acid labile group in the case of a chemically amplified positive photoresist material. The repeating unit having an acid labile group is preferably a repeating unit represented by the following formula (b1) (hereinafter also referred to as repeating unit b1) or a repeating unit represented by the following formula (b2) (hereinafter also referred to as repeating unit b2). good. [Chemical 25]

In the formula, R ^{A is} each independently a hydrogen atom or a methyl group. Y ¹ is a single bond, a phenyl group or a naphthyl group extension, or a group selected from an ester containing a lactone ring, and in at least one of the carbon atoms of the linking group having 1 to 12. Y ² is a single bond or an ester group. R ¹¹ and R ¹² are each independently an acid-labile group. R ¹³ is a halogen atom, trifluoromethyl, cyano, linear, branched or cyclic alkyl or alkoxy group having 1 to 6 carbon atoms, or linear, branched or cyclic carbon number 2-7 fluorenyl, fluorenyl or alkoxycarbonyl. R ¹⁴ is a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms, and a part of its carbon atom may be substituted with an ether group or an ester group. p is 1 or 2. q is an integer from 0 to 4.

Examples of the repeating unit b1 include, but are not limited to, the following. In the following formula, R ^A and R ^{11 are the} same as described above. [Chem. 26]

Examples of the repeating unit b2 include, but are not limited to, the following. In the following formula, R ^A and R ^{12 are the} same as described above. [Chemical 27]

In the formulae (b1) and (b2), the acid-labile groups represented by R ¹¹ and R ¹² are described in, for example, Japanese Patent Application Laid-Open No. 2013-80033 and Japanese Patent Application Laid-Open No. 2013-83821.

Typical examples of the acid-labile group include those represented by the following formulae (AL-1) to (AL-3). [Chemical 28]

In the formulae (AL-1) and (AL-2), R ²¹ and R ²⁴ are a monovalent hydrocarbon group having 1 to 40 carbon atoms, such as a linear, branched, or cyclic alkyl group, and preferably 1 to 20, It may contain a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. R ²² and R ²³ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms such as a linear, branched, or cyclic alkyl group, and may further include an oxygen atom, a sulfur atom, a nitrogen atom, and fluorine Atoms and other heteroatoms. And both R ^22, R ^23, and any one of R ²⁴ may be bonded to each other and to which they are bonded and the carbon atom or carbon atoms and oxygen atoms together form a 3 to 20 carbon atoms, preferably 4 to 16 of Rings, especially alicyclic rings. k is an integer from 0 to 10, preferably from 1 to 5.

In formula (AL-3), R ²⁵ , R ^26, and R ²⁷ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms such as a linear, branched, or cyclic alkyl group, and may contain an oxygen atom and sulfur Atoms, nitrogen atoms, fluorine atoms and other heteroatoms. In addition, any one of R ²⁵ , R ²⁶ and R ²⁷ may be bonded to each other and together with the carbon atoms to which they are bonded, may form a ring having 3 to 20 carbon atoms, preferably 4 to 16, particularly an alicyclic ring.

When the polymer-bonded acid generator also functions as a base polymer, the polymer-bonded acid generator may further include a repeating unit c containing a phenolic hydroxyl group as an adhesive group. Examples of the monomer to which the repeating unit c is given are as follows, but are not limited thereto. In the following formula, R ^{A is the} same as described above.

[Chem. 29]

When the polymer-bonded acid generator also functions as a base polymer, it may further contain hydroxyl groups other than phenolic hydroxyl groups, carboxyl groups, lactone rings, ether groups, ester groups, carbonyl groups, or cyano groups as the adhesion. Based on the repeating unit d. Examples of the monomer to which the repeating unit d is given include, but are not limited to, the following. In the following formula, R ^{A is the} same as described above.

[Hua 30]

[Chemical 31]

[Chemical 32]

[Chemical 33]

[Chem 34]

[Chem. 35]

[Chemical 36]

[Chem. 37]

[Chemical 38]

In the case of a monomer containing a hydroxyl group, the hydroxyl group may be substituted with an acetoxy group such as ethoxyethoxy group which is easily deprotected by an acid during polymerization, and then deprotected with a weak acid and water after polymerization, or acetamidine may be used first. Group, methylamidino, trimethylacetamido and the like, and subjected to alkali hydrolysis after polymerization.

When the polymer-bonded acid generator also functions as a base polymer, it may further contain indene, benzofuran, benzothiophene, vinylnaphthalene, chromone, coumarin, norbornadiene, or the And other derivatives of repeating unit e. Examples of the monomers that give the repeating unit e include, but are not limited to, the following.

[Chemical 39]

When the polymer-bonded acid generator also functions as a base polymer, it may contain a repeating unit f derived from dihydroindene, vinylpyridine, or vinylcarbazole.

The polymer-bonded acid generator may contain a repeating unit g derived from a polymerizable unsaturated bond-containing onium salt other than the repeating units a1 and a2. Examples of such a repeating unit g include those described in paragraph [0060] of Japanese Patent Application Laid-Open No. 2017-008181.

The basic polymer used in the positive type photoresist material includes repeating units a1 and / or a2 and repeating units b1 and / or b2 having acid labile groups as essential units. In this case, the content ratios of the repeating units a1, a2, b1, b2, c, d, e, f, and g are preferably 0 ≦ a1 <1.0, 0 ≦ a2 <1.0, 0 <a1 + a2 <1.0, 0 ≦ b1 <1.0, 0 ≦ b2 <1.0, 0 <b1 + b2 <1.0, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, and 0 ≦ g ≦ 0.4, more preferably 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.02 ≦ a1 + a2 ≦ 0.7, 0 ≦ b1 ≦ 0.9, 0 ≦ b2 ≦ 0.9, 0.1 ≦ b1 + b2 ≦ 0.9, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7, and 0 ≦ g ≦ 0.3, and more preferably 0 ≦ a1 ≦ 0.5, 0 ≦ a2 ≦ 0.5, 0.03 ≦ a1 + a2 ≦ 0.5, 0 ≦ b1 ≦ 0.8, 0 ≦ b2 ≦ 0.8, 0.1 ≦ b1 + b2 ≦ 0.8, 0 ≦ c ≦ 0.7, 0 ≦ d ≦ 0.7, 0 ≦ e ≦ 0.6, 0 ≦ f ≦ 0.6, and 0 ≦ g ≦ 0.2. In addition, a1 + a2 + b1 + b2 + c + d + e + f + g = 1.0.

On the other hand, the base polymer for negative photoresist materials does not necessarily require an acid labile group, and repeating units a1 and / or a2 are necessary units. Examples include repeating units c, d, e, f, and / or g person. The content ratio of these repeating units is preferably 0 ≦ a1 <1.0, 0 ≦ a2 <1.0, 0 <a1 + a2 <1.0, 0 <c <1.0, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, and 0 ≦ g ≦ 0.4, more preferably 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.02 ≦ a1 + a2 ≦ 0.7, 0.2 ≦ c <1.0, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7 and 0 ≦ g ≦ 0.3, and more preferably 0 ≦ a1 ≦ 0.5, 0 ≦ a2 ≦ 0.5, 0.03 ≦ a1 + a2 ≦ 0.5, 0.3 ≦ c <1.0, 0 ≦ d ≦ 0.75, 0 ≦ e ≦ 0.6 , 0 ≦ f ≦ 0.6, and 0 ≦ g ≦ 0.2. In addition, a1 + a2 + c + d + e + f + g = 1.0.

In order to synthesize the polymer-bonded acid generator, for example, a monomer to which the repeating unit is given may be polymerized by adding a radical polymerization initiator to an organic solvent and heating the monomer.

Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and diethyl ether. Alkanes, etc. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethylvaleronitrile), and 2,2-azobis (2 -Methyl propionate) dimethyl, benzamidine peroxide, lauryl peroxide, and the like. The temperature during the polymerization is preferably 50 to 80 ° C. The reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

When hydroxystyrene and hydroxyvinylnaphthalene are copolymerized, hydroxystyrene and hydroxyvinylnaphthalene can be replaced with ethoxylated styrene and ethoxylated vinylnaphthalene, and the polymer can be hydrolyzed by the aforementioned base after polymerization. Then, the ethoxy group is deprotected, and hydroxystyrene units and hydroxyvinylnaphthalene units are formed.

The alkali used in the alkali hydrolysis may be ammonia water, triethylamine, or the like. The reaction temperature is preferably -20 to 100 ° C, and more preferably 0 to 60 ° C. The reaction time is preferably 0.2 to 100 hours, and more preferably 0.5 to 20 hours.

When the polymer-bonded acid generator uses THF as a solvent and measures polystyrene-equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC), it is preferably 1,000 to 500,000, and more preferably 2,000 to 500,000. 30,000. When Mw is in the aforementioned range, the heat resistance of the photoresist material is good.

When the molecular weight distribution (Mw / Mn) of the polymer-bonded acid generator is wide, there may be foreign matter on the pattern or the shape of the pattern may deteriorate due to the presence of a low molecular weight and high molecular weight polymer. . As the pattern is regularly refined, the influence of Mw and molecular weight distribution tends to increase. Therefore, in order to obtain a photoresist material suitable for fine pattern size, the molecular weight distribution of the aforementioned polymer-bonded acid generator is 1.0 to 2.0, especially 1.0 to A narrow dispersion of 1.5 is preferred.

The polymer-bonded acid generator may contain two or more polymers having different composition ratios, Mw, and molecular weight distributions.

[Other components] The polymer-bonded acid generator is appropriately combined with other acid generators, organic solvents, surfactants, dissolution inhibitors, cross-linking agents, quenchers, etc. in accordance with the purpose, and is constituted. The positive photoresist material and the negative photoresist material, in the exposure part, the aforementioned base polymer accelerates the dissolution rate of the developing solution due to the catalyst reaction, and can become a highly sensitive positive photoresist material and negative photoresist material. In this case, the photoresist film has high dissolution contrast and resolvability, has exposure margin, excellent processing adaptability, good shape of the pattern after exposure, and can particularly suppress acid diffusion, so the density difference is small, so it is practical It is very effective as a photoresist material for super LSI. In particular, if it is made of a chemically-amplified positive-type photoresist material using an acid catalyst reaction, the sensitivity will be higher, and the characteristics will be better, which is extremely useful.

The photoresist material of the present invention may contain an acid generator (hereinafter referred to as another acid generator) other than the aforementioned polymer-bonded acid generator as long as the effect of the present invention is not impaired. Other acid generators include compounds (photoacid generators) that generate an acid by sensing active light or radiation. It does not matter if the photoacid generator is a compound that generates acid due to high-energy ray irradiation, and it is preferably one that generates sulfonic acid, sulfamic acid, or methylated acid. Preferred photoacid generators include sulfonium salts, sulfonium salts, sulfonyldiazomethane, N-sulfonyloxyfluorenimine, oxime-O-sulfonate type acid generators, and the like. Specific examples of the acid generator include those described in paragraphs [0122] to [0142] of Japanese Patent Application Laid-Open No. 2008-111103.

As the photoacid generator, a sulfonium salt represented by the following formula (1-1) and a sulfonium salt represented by the following formula (1-2) can be suitably used. [Chemical 40]

In the formulae (1-1) and (1-2), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ^104, and R ¹⁰⁵ each independently represent a linear, branched, or cyclic carbon number that may contain a hetero atom. A monovalent hydrocarbon group of 1-20. In addition, any one of R ¹⁰¹ , R ¹⁰² and R ¹⁰³ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

Examples of the cationic moiety of the phosphonium salt represented by the formula (1-1) include the same ones as the aforementioned cationic moiety of the repeating unit a1. The cationic moiety of the phosphonium salt represented by the formula (1-2) may be the same as the cationic moiety of the repeating unit a2 described above.

In the formula (1-1) and (1-2), X ^- ~ represents the sum (1D) anion is selected from the following formulas (1A). [Chemical 41]

In the formula (1A), R ^fa represents a fluorine atom or a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom.

The anion represented by the formula (1A) is preferably one represented by the following formula (1A '). [Chemical 42]

In the formula (1A ′), R ¹⁰⁶ represents a hydrogen atom or a trifluoromethyl group, and preferably a trifluoromethyl group. R ¹⁰⁷ represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 38 carbon atoms which may contain a hetero atom. The aforementioned hetero atom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom or the like, and an oxygen atom is more preferable. In terms of the aforementioned monovalent hydrocarbon group, considering the viewpoint of obtaining high resolution when a fine pattern is formed, it is particularly preferable to have a carbon number of 6 to 30. The aforementioned monovalent hydrocarbon group is preferably methyl, ethyl, propyl, isopropyl, butyl, isobutyl, second butyl, third butyl, pentyl, neopentyl, cyclopentyl, hexyl, cyclo Hexyl, 3-cyclohexenyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptyl, 1-adamantyl, 2-adamantyl, 1 -Adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, dicyclohexylmethyl, eicosyl, allyl, Benzyl, diphenylmethyl, tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy ) Methyl, ethoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, and the like. In addition, a part of the hydrogen atoms of these groups may be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these groups may be substituted with an oxygen atom or sulfur. A hetero atom group such as an atom or a nitrogen atom, as a result, it may contain a hydroxyl group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonate group, a carbonate group, a lactone ring, a sultone ring, a carboxylic acid anhydride, Haloalkyl, etc.

For the synthesis of a sulfonium salt containing an anion represented by the formula (1A '), refer to Japanese Patent Application Laid-Open No. 2007-145797, Japanese Patent Application No. 2008-106045, Japanese Patent Application No. 2009-7327, and Japanese Patent Application No. 2009- Bulletin 258695 and the like. In addition, osmium salts described in Japanese Patent Application Laid-Open No. 2010-215608, Japanese Patent Application Laid-Open No. 2012-41320, Japanese Patent Application Laid-Open No. 2012-106986, Japanese Patent Application Laid-Open No. 2012-153644, and the like can also be appropriately used.

Examples of the anion represented by the formula (1A) include, but are not limited to, the following. Moreover, in the following formula, Ac is ethenyl.

[Chemical 43]

[Chemical 44]

[Chemical 45]

[Chemical 46]

In formula (1B), R ^fb1 and R ^fb2 each independently represent a fluorine atom or a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. Examples of the aforementioned monovalent hydrocarbon group are the same as those listed in the description of R ¹⁰⁷ . R ^fb1 and R ^{fb2 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. In addition, R ^fb1 and R ^fb2 may be bonded to each other and form a ring together with the group to which they are bonded (-CF ₂ -SO ₂ -N ^-- SO ₂ -CF _2- ). It is particularly preferable to use fluorinated ethyl group. Or fluorinated propylidene is preferred to form a ring structure.

In formula (1C), R ^fc1 , R ^fc2, and R ^fc3 each independently represent a fluorine atom or a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. Examples of the aforementioned monovalent hydrocarbon group are the same as those listed in the description of R ¹⁰⁷ . R ^fc1 , R ^fc2 and R ^{fc3 are} preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. In addition, R ^fc1 and R ^fc2 may be bonded to each other and form a ring together with the group to which they are bonded (-CF ₂ -SO ₂ -C ^-- SO ₂ -CF _2- ), and it is particularly preferable to use fluorinated ethyl 2, Fluorinated propyl group is preferred to form a ring structure.

In formula (1D), R ^fd represents a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. Examples of the aforementioned monovalent hydrocarbon group are the same as those listed in the description of R ¹⁰⁷ .

For the synthesis of a sulfonium salt containing an anion represented by formula (1D), see Japanese Patent Application Laid-Open No. 2010-215608 and Japanese Patent Application Laid-Open No. 2014-133723.

Examples of the anion represented by the formula (1D) include, but are not limited to, the following.

[Chemical 47]

In addition, a photoacid generator containing an anion represented by the formula (1D) does not have fluorine at the α position of the sulfo group, but because there are two trifluoromethyl groups at the β position, it has the instability to stabilize the acid in the photoresist polymer. The base is cut to a sufficient acidity. Therefore, it can be used as a photoacid generator.

Moreover, it is also suitable to use the one represented by the following formula (2) as a photo-acid generator. [Chemical 48]

In Formula (2), R ²⁰¹ and R ²⁰² are each independently a monovalent hydrocarbon group having 1 to 30 carbon atoms, which may be a linear, branched, or cyclic heteroatom. R ²⁰³ is a straight-chain may contain hetero atoms, branched or cyclic having 1 to 30 carbon atoms of the divalent hydrocarbon group. Further, any one of R ²⁰¹ , R ²⁰² and R ²⁰³ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. L ^A is a single bond, an ether group, or a linear, branched, or cyclic bivalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. X ^A , X ^B , X ^C and X ^D are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group. However, at least one of X ^A , X ^B , X ^C and X ^D is a fluorine atom or a trifluoromethyl group. k is an integer from 0 to 3.

Examples of the monovalent hydrocarbon group include methyl, ethyl, propyl, isopropyl, n-butyl, second butyl, third butyl, n-pentyl, third pentyl, n-hexyl, n-octyl, and n-butyl. Nonyl, n-decyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclo Hexylbutyl, norbornyl, oxordinyl, tricyclo [5.2.1.0 ^2,6 ] decyl, adamantyl, phenyl, naphthyl, anthracenyl, and the like. In addition, part of the hydrogen atoms of these groups may be substituted with hetero atoms such as oxygen, sulfur, nitrogen, and halogen atoms, and part of the carbon atoms of these groups may be substituted with oxygen, sulfur, and nitrogen atoms. Such a heteroatom group may contain a hydroxyl group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonate group, a carbonate group, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, and the like.

Examples of the divalent hydrocarbon group include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-. Diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11 -Diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecyl Straight-chain alkane diyl such as alkane-1,16-diyl, heptadecane-1,17-diyl; cyclopentane diyl, cyclohexane diyl, norbornane diyl, adamantane diyl, etc. Saturated cyclic divalent hydrocarbon groups; unsaturated cyclic divalent hydrocarbon groups such as phenylene and naphthyl. In addition, part of the hydrogen atoms of these groups may be substituted with alkyl groups such as methyl, ethyl, propyl, n-butyl, and third butyl, and part of the hydrogen atoms of these groups may be substituted with oxygen atoms. , A sulfur atom, a nitrogen atom, a halogen atom, or a heteroatom group, or a part of a carbon atom of such a group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, it may contain a hydroxyl group , Cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sultone ring, carboxylic anhydride, haloalkyl, etc. The aforementioned hetero atom is preferably an oxygen atom.

The photoacid generator represented by the formula (2) is preferably one represented by the following formula (2 '). [Chemical 49]

In formula (2 '), L ^{A is the} same as described above. R is a hydrogen atom or a trifluoromethyl group, and preferably a trifluoromethyl group. R ³⁰¹ , R ^302, and R ³⁰³ are each independently a hydrogen atom or a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Examples of the aforementioned monovalent hydrocarbon group are the same as those listed in the description of R ¹⁰⁷ . x and y are each independently an integer of 0-5. z is an integer from 0 to 4.

Examples of the photoacid generator represented by the formula (2) include, but are not limited to, the following. In the following formula, R is the same as described above, and Me represents a methyl group.

[Chemical 50]

[Chemical 51]

[Chemical 52]

Among the photoacid generators, those containing an anion represented by the formula (1A ′) or (1D) are particularly preferable because they have a small acid diffusion and excellent solubility in a photoresist solvent. In addition, those containing an anion represented by the formula (2 ') have extremely low acid diffusion and are particularly preferred.

For other acid generators, the sulfonium salt and sulfonium salt of fluorinated sulfonic acid containing iodinated benzamyloxy group represented by the following formula (3-1) or (3-2) can also be used. [Chem 53]

In formulae (3-1) and (3-2), R ³¹ is a hydrogen atom, a hydroxyl group, a carboxyl group, a nitro group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an amine group, or a fluorine atom or chlorine Atoms, bromine atoms, hydroxyl, amine or alkoxy linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, and alkane having 2 to 20 carbon atoms Oxycarbonyl, alkoxy having 2 to 20 carbons or alkylsulfonoxy having 1 to 4 carbons, or -NR ³⁷ -C (= O) -R ³⁸ or -NR ³⁷ -C (= O) -OR ³⁸ , R ³⁷ is a hydrogen atom, or a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms which may contain a halogen atom, a hydroxyl group, an alkoxy group, a fluorenyl group, or a fluorenyl group, R ³⁸ is a linear, branched or cyclic alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and may also contain a halogen atom, a hydroxyl group, and an alkoxy group. Radical, fluorenyl or fluorenyl. X ¹¹ r is based on a single bond or a carbon number of 1 to 20 when the divalent linking group, and r is based on a carbon number of 1 to 20 trivalent or tetravalent linking group is 2 or 3, the linking group may contain Oxygen, sulfur, or nitrogen. Rf ¹¹ to Rf ¹⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Rf ¹¹ and Rf ¹² may be combined to form a carbonyl group. R ³² , R ³³ , R ³⁴ , R ³⁵ and R ³⁶ are each independently a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched or cyclic carbon number 2 Alkenyl of ~ 12, straight chain, branched or cyclic alkynyl of 2 to 12 carbons, aryl of 6 to 20 carbons, or aralkyl or aryloxyalkyl of 7 to 12 carbons And some or all of the hydrogen atoms of these groups can also be substituted with hydroxyl, carboxyl, halogen, cyano, pendant oxy, amido, nitro, sultone, fluorenyl, or sulfonium-containing groups Ether groups, ester groups, carbonyl groups, carbonate groups, or sulfonate groups can also be inserted between the carbon atoms of these groups. R ³² and R ³³ may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. r is an integer from 1 to 3. s is an integer from 1 to 5. t is an integer from 0 to 3.

For other acid generators, a phosphonium sulfonic acid salt of a fluorinated sulfonic acid containing iodized phenoxy or iodized phenylalkoxy represented by the following formula (3-3) or (3-4) may be used Or phosphonium salt as an acid generator. [Chem. 54]

In the formulae (3-3) and (3-4), each of R ^{41 is} independently a hydroxyl group, a linear chain, a branched or cyclic alkyl group or an alkoxy group having 1 to 20 carbon atoms, a linear chain, or a branch The ammonium or alkoxy group with a carbon number of 2 to 20, or a cyclic ring, a fluorine atom, a chlorine atom, a bromine atom, an amine group, or an alkoxycarbonyl group is substituted for the amine group. R ^{42 is} each independently a single bond or an alkylene group having 1 to 4 carbon atoms. R ⁴³ is a single bond or a divalent linking group having 1 to 20 carbon atoms when u is 1, and a trivalent or tetravalent linking group having 1 to 20 carbon atoms when u is 2 or 3, and the linking group is also It may contain an oxygen atom, a sulfur atom, or a nitrogen atom. Rf ²¹ to Rf ²⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Rf ²¹ and Rf ²² may be combined to form a carbonyl group. R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , R ⁴⁷ and R ⁴⁸ are each independently a linear, branched or cyclic alkyl group having 1 to 12 carbons, a linear, branched or cyclic carbon number 2 Alkenyl groups of ~ 12, aryl groups of 6 to 20 carbons, or aralkyl or aryloxyalkyl groups of 7 to 12 carbons, and part or all of the hydrogen atoms of these groups may also be substituted with hydroxyl or carboxyl groups , Halogen atom, cyano group, pendant oxy group, amido group, nitro group, sultone group, fluorenyl group or sulfonium salt-containing group, ether groups and ester groups can also be inserted between the carbon-carbon bonds of these groups , Carbonyl, carbonate or sulfonate. And, R ⁴⁴ and R ⁴⁵ may be bonded to each other and to which they are bonded form a ring together with the sulfur atom. u is an integer from 1 to 3. v is an integer from 1 to 5. w is an integer from 0 to 3.

Examples of the cationic moiety of the phosphonium salt represented by the formulae (3-1) and (3-3) include those in which the cationic moiety of the repeating unit a1 is the same as described above. The cationic moiety of the phosphonium salt represented by the formulae (3-2) and (3-4) may be the same as the cationic moiety of the repeating unit a2 described above.

Examples of the anion part of the onium salt represented by the formulae (3-1) to (3-4) include, but are not limited to, the following.

[Chem 55]

[Chemical] 56

[Chemical] 57

[Chemical] 58

[Chemical 59]

[Chemical 60]

[Chem. 61]

[Chem 62]

[Chem 63]

[Chemical 64]

[Chem. 65]

[Chemical 66]

[Chemical 67]

[Chemical 68]

[Chemical 69]

[Chemical 70]

[Chemical 71]

[Chemical 72]

[Chemical 73]

[Chemical 74]

[Chemical 75]

[Chemical 76]

The content of the other acid generator is preferably 0 to 200 parts by mass, and more preferably 0.1 to 100 parts by mass, relative to 100 parts by mass of the base polymer.

In the case of a positive-type photoresist material, by dissolving a dissolution inhibitor, the dissolution speed difference between the exposed portion and the unexposed portion can be further increased, and the resolution can be improved. In the case of a negative-type photoresist material, by adding a cross-linking agent, the dissolution rate of the exposed portion is reduced, and a negative pattern can be obtained.

Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 3-methoxybutan described in paragraphs [0144] to [0145] of Japanese Patent Application Laid-Open No. 2008-111103. Alcohols, alcohols such as 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl Ethers, ethers such as propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, dimethyl glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate Esters, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, third butyl acetate, third butyl propionate, propylene glycol mono third butyl ether acetate, etc. Lactones, lactones such as γ-butyrolactone, and mixed solvents thereof.

In the photoresist material of the present invention, the content of the aforementioned organic solvent is preferably 0 to 10,000 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 200 to 8,000 parts by mass.

Examples of the surfactant include those described in paragraphs [0165] to [0166] of Japanese Patent Application Laid-Open No. 2008-111103. By adding a surfactant, the coating property of the photoresist material can be made better or controlled. In the photoresist material of the present invention, the content of the surfactant is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer.

As the aforementioned dissolution inhibitor, a hydrogen atom of the phenolic hydroxyl group of a compound having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule may be mentioned. Compounds substituted with acid labile groups at a ratio of 0 to 100 mole%, or compounds containing a carboxyl group in the molecule. The hydrogen atoms of the carboxyl group are replaced with acid labile groups at an average ratio of 50 to 100 mole% as a whole. Based compounds. Specifically, bisphenol A, phenol, phenol phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, hydroxy group of cholic acid, and hydrogen atom of carboxyl group are substituted with acid labile groups. The resulting compounds are described in paragraphs [0155] to [0178] of Japanese Patent Application Laid-Open No. 2008-122932, for example.

When the photoresist material of the present invention is a positive type photoresist material, the content of the dissolution inhibitor relative to 100 parts by mass of the base polymer is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass.

Examples of the crosslinking agent include an epoxy compound, a melamine compound, a guanamine compound, and a glycoluril, which are substituted with at least one group selected from the group consisting of methylol, alkoxymethyl, and methyloxymethyl. Compounds, urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as ene ether groups, and the like. They can be used as additives or can be introduced into polymer side chains as pendant groups. Moreover, a compound containing a hydroxyl group can also be used as a crosslinking agent.

Examples of the epoxy compound include (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and trihydroxyethylethyl Alkane triglycidyl ether and the like.

Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, methoxymethylated compounds of 1 to 6 methylol groups of hexamethylolmelamine, or mixtures thereof, and hexamethoxyethylmelamine , Hexamethyloxymethyl melamine, 1-6 methylol groups of hexamethylolmelamine, methylolated compounds or mixtures thereof.

Examples of the guanamine compounds include tetramethylolguanamine, tetramethoxymethylguanamine, methoxymethylated compounds of 1 to 4 methylol groups of tetramethylolguanamine, or mixtures thereof, tetramethyl A compound or a mixture thereof in which 1 to 4 methylol groups of oxyethylguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine are methylated with methoxyl.

Examples of glycoluril compounds include 1 to 4 of hydroxymethyl groups of tetramethylol glycoluril, tetramethoxyglycol urea, tetramethoxymethyl glycoluril, and tetramethylol glycoluril. Compounds or mixtures thereof, 1-4 methylol groups or mixtures of methylol groups of tetramethylol glycoluril, and the like. Examples of the urea compound include tetramethylolurea, tetramethoxymethylurea, methoxymethylated compounds of 1 to 4 methylol groups of tetramethylolurea, or mixtures thereof, and tetramethoxyethyl Urea and so on.

Examples of the isocyanate compound include methylenephenyl diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylenebisazide, 4,4'-oxybisazide, and the like.

Examples of the compound containing an olefin ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butanediol divinyl ether, and tetramethylene glycol diethylene glycol. Vinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, neopentyl tetraol trivinyl ether, new Pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane trivinyl ether, and the like.

When the photoresist material of the present invention is a negative type photoresist material, the content of the crosslinking agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass relative to 100 parts by mass of the base polymer.

A quenching agent may also be added to the photoresist material of the present invention. Examples of the quencher include conventional basic compounds. Conventional basic compounds include primary, secondary and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen compounds with carboxyl groups, nitrogen compounds with sulfonyl groups Compounds, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amidines, amidines, carbamates, and the like. In particular, paragraphs [0146] to [0164] of Japanese Patent Application Laid-Open No. 2008-111103 describe primary, secondary, and tertiary amine compounds, in particular, hydroxyl groups, ether groups, ester groups, lactone rings, cyano groups, and sulfonic acids. Ester-based amine compounds or urethane-based compounds described in Japanese Patent No. 3790649 are preferred. By adding such a basic compound, for example, the diffusion rate of the acid in the photoresist film can be more suppressed, or the shape can be corrected.

Examples of the quencher include onium salts such as sulfonium salts, sulfonium salts, and ammonium salts of α-position unfluorinated sulfonic acids. The α-fluorinated sulfonic acid, phosphonium imine or methylated acid is necessary to deprotect the acid labile group of the carboxylic acid ester, but the salt is exchanged with the α-unfluorinated onium salt. Can release α-position unfluorinated sulfonic acid or carboxylic acid. The α-position unfluorinated sulfonic acid and carboxylic acid act as quenchers because they do not cause deprotection reactions.

It is also suitable to use an onium carboxylate salt represented by the following formula (4) as a quencher. [Chemical 77]

In the formula, R ⁴⁰¹ represents a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. M _A ⁺ represents an onium ion. Examples of the onium ion include a sulfonium ion, a sulfonium ion, and an ammonium ion.

The anion portion of the carboxylate is preferably represented by the following formula (5). [Chem. 78]

R ⁴⁰² and R ⁴⁰³ each independently represent a hydrogen atom, a fluorine atom, or a trifluoromethyl group. R ⁴⁰⁴ represents a hydrogen atom, a hydroxyl group, a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, which may contain a hetero atom.

Examples of the quencher include a polymer-type quencher described in Japanese Patent Application Laid-Open No. 2008-239918. It improves the rectangularity of the photoresist after pattern formation by aligning the photoresist surface after coating. The polymer type quenching agent has the effect of preventing the loss of the film of the pattern and the rounding of the top of the pattern when the protective film for wet exposure is used.

In the photoresist material of the present invention, the content of the quencher is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer, and more preferably 0 to 4 parts by mass.

The photoresist material of the present invention may also be blended with a polymer compound (water repellency improving agent) for improving the water repellency of the photoresist surface after spin coating. The aforementioned water repellent enhancer can be used in the immersion lithography without using a top coat. The aforementioned water repellency enhancer is preferably a polymer compound containing a fluorinated alkyl group, a polymer compound containing a specific structure containing 1,1,1,3,3,3-hexafluoro-2-propanol residue, etc. Examples such as Japanese Patent Application Laid-Open No. 2007-297590 and Japanese Patent Application Laid-Open No. 2008-111103 are more preferable. The aforementioned water repellent enhancer needs to be dissolved in an organic solvent developer. The specific water-repellent enhancer having a 1,1,1,3,3,3-hexafluoro-2-propanol residue as described above has good solubility in a developing solution. As for the water repellent enhancer, a polymer compound containing a repeating unit of an amine group and an amine salt can prevent the acid in PEB from evaporating and prevent poor opening of the pore pattern after development. In the photoresist material of the present invention, the content of the water repellent enhancer is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass relative to 100 parts by mass of the base polymer.

The photoresist material of the present invention may be blended with acetylene alcohols. Examples of the acetylene alcohols include those described in paragraphs [0179] to [0182] of Japanese Patent Application Laid-Open No. 2008-122932. In the photoresist material of the present invention, the content of acetylene alcohols is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer.

[Pattern forming method] When the photoresist material of the present invention is used in the manufacture of various integrated circuits, a well-known lithography technique can be adopted.

For example, the positive photoresist material of the present invention is applied to a substrate (Si, SiO ₂ , Si, SiO ₂ , on SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a mask for producing the circuit board (Cr, CrO, CrON, MoSi 2, SiO 2 , etc.), the coated film thickness of 0.01 ~ 2.0 μm. Pre-baking it on a hot plate, preferably at 60-150 ° C for 10 seconds to 30 minutes, and more preferably at 80-120 ° C for 30 seconds to 20 minutes. Secondly, high-energy rays such as ultraviolet rays, extreme ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, and the like are exposed through a predetermined mask or directly through the target pattern. The exposure amount is preferably about 1 to 200 mJ / cm ² , especially about 10 to 100 mJ / cm ² , or about 0.1 to 100 μC / cm ² , and especially about 0.5 to 50 μC / cm ² . The PEB is then preferably performed on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, and more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes.

Then use 0.1 to 10% by mass, preferably 2 to 5% by mass of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium The developing solution of an alkaline aqueous solution such as ammonium hydroxide (TBAH) is performed for 3 seconds to 3 minutes by a conventional method such as a dip method, a puddle method, and a spray method, and preferably 5 seconds to 2 minutes. Develop to dissolve the irradiated part in the developing solution, and the unexposed part will not be dissolved to form the intended positive pattern on the substrate. In the case of negative photoresist, it is the opposite of the case of positive photoresist, that is, the light-exposed part is insoluble in the developing solution, and the unexposed part is dissolved. In addition, the photoresist material of the present invention is particularly suitable for utilizing the fine patterns of KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, γ-ray, synchrotron radiation in high-energy rays. Into.

It is also possible to use a positive-type photoresist material containing a base polymer containing an acid-labile group to perform negative development using organic solvent development to obtain a negative pattern. Examples of the developer used in this case include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutanone, and methyl formaldehyde. Methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, Isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid, methyl propionate, ethyl propionate, 3-ethoxy Ethyl propionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyrate Ethyl ester, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, phenyl methyl acetate, benzyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate , Ethyl phenylacetate, 2-phenylethyl acetate, and the like. These organic solvents may be used alone or in combination of two or more.

Rinse at the end of development. The eluent is preferably a solvent that is miscible with the developing solution and does not dissolve the photoresist film. Such a solvent is preferably an alcohol having 3 to 10 carbons, an ether compound having 8 to 12 carbons, an alkane having 6 to 12 carbons, an olefin, an alkyne, or an aromatic solvent.

Specific examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, third butanol, 1-pentanol, 2-pentanol, 3-pentanol, tertiary pentanol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1- Hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol Alcohol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol Alcohol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol Alcohol, cyclohexanol, 1-octanol, etc.

The ether compound having 8 to 12 carbon atoms can be selected from the group consisting of di-n-butyl ether, di-isobutyl ether, di-second butyl ether, di-n-pentyl ether, di-isopentyl ether, di-second pentyl ether, di-third pentyl ether, One or more solvents in di-n-hexyl ether.

Examples of the alkane having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, and methyl formaldehyde. Cyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane and the like. Examples of the olefin having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of the alkyne having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

Examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, third butylbenzene, and mesitylene.

Rinse can be used to reduce the occurrence of photoresist pattern collapse and defects. In addition, leaching is not necessary, and the amount of solvent used can be reduced by not performing leaching.

The developed hole pattern and trench pattern can also be shrunk by heat flow, RELACS technology or DSA technology. The shrinkage agent is coated on the hole pattern, and the acid catalyst in the baking diffuses from the photoresist layer to cause cross-linking of the shrinkage agent on the surface of the photoresist. The baking temperature is preferably 70 to 180 ° C, more preferably 80 to 170 ° C, and the time is preferably 10 to 300 seconds. The excess shrinkage agent is removed and the hole pattern is reduced. [Example]

The present invention will be specifically described by the following synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

PAG monomers 1 to 7 used in the synthesis examples and comparative PAG monomer 1 are as follows. [Chemical 79]

[Synthesis Example 1] Synthesis of polymer 1 In a 2L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.6 g of 4-hydroxyphenyl methacrylate, and 3-side methacrylic acid were charged. 4.5 g of oxy-2,7-dioxatricyclo [4.2.1.0 ^4,8 ] nonane-9-ester, 8.1 g of PAG monomer 1, and 40 g of THF as a solvent. This reaction vessel was cooled to -70 ° C in a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blowing was repeated 3 times. After the temperature was raised to room temperature, 1.2 g of AIBN as a polymerization initiator was added, and the temperature was raised to 60 ° C, followed by a reaction for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropanol, and the obtained white solid was filtered and dried under reduced pressure at 60 ° C to obtain a white solid of polymer 1. The composition of polymer 1 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 80]

[Synthesis Example 2] Synthesis of polymer 2 A polymer 2 was obtained as a white solid in the same manner as in Synthesis Example 1 except that PAG monomer 1 was replaced with 10.3 g of PAG monomer 2. The composition of polymer 2 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chem. 81]

[Synthesis Example 3] Synthesis of Polymer 3 A polymer 3 was obtained as a white solid in the same manner as in Synthesis Example 1 except that PAG monomer 1 was replaced with 10.3 g of PAG monomer 3. The composition of polymer 3 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 82]

[Synthesis Example 4] Synthesis of Polymer 4 Polymer PA 4 was obtained as a white solid in the same manner as in Synthesis Example 1 except that PAG monomer 1 was replaced with 9.3 g of PAG monomer 4. The composition of polymer 4 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 83]

[Synthesis Example 5] Synthesis of polymer 5 In a 2L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 4.8 g of 4-hydroxystyrene, and 9.1 g of PAG monomer 5 were charged as 40 g of solvent in THF. This reaction vessel was cooled to -70 ° C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blowing was repeated 3 times. After the temperature was raised to room temperature, 1.2 g of AIBN as a polymerization initiator was added. After the temperature was raised to 60 ° C, the reaction was allowed to proceed for 15 hours. This reaction solution was precipitated in a 1 L solution of isopropanol, and the obtained white solid was filtered and dried under reduced pressure at 60 ° C to obtain a polymer 5 as a white solid. The composition of polymer 5 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 84]

[Synthesis Example 6] Synthesis of Polymer 6 In the same manner as in Synthesis Example 5 except that PAG monomer 5 was replaced with 7.1 g of PAG monomer 6, Polymer 6 was obtained as a white solid. The composition of polymer 6 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 85]

[Synthesis Example 7] Synthesis of Polymer 7 A PAG monomer 5 was replaced with 9.2 g of PAG monomer 7. The polymer 7 was obtained as a white solid in the same manner as in Synthesis Example 5. The composition of polymer 7 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 86]

[Synthesis Example 8] Synthesis of polymer 8 1-methyl-1-cyclopentyl methacrylate was replaced with 13.5 g of 4-pentoxy-3-fluorostyrene, and 3.0 g of 4-hydroxystyrene was used. A polymer 8 was obtained as a white solid in the same manner as in Synthesis Example 7 except that the polymer 8 was obtained. The composition of polymer 8 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chemical 87]

[Comparative Synthesis Example 1] Synthesis of Comparative Polymer 1 Comparative PAG 1 was obtained in the same manner as in Synthesis Example 1 except that PAG monomer 1 was replaced with 7.6 g of comparative PAG monomer 1. The composition of Comparative Polymer 1 was confirmed by ¹³ C-NMR and ¹ H-NMR, and Mw and Mw / Mn were confirmed by GPC.

[Chem 88]

[Examples 1 to 11, Comparative Example 1] (1) Preparation of photoresist material In a solvent in which 100 ppm of FC-4430 manufactured by 3M was dissolved as a surfactant, each composition was dissolved in accordance with the composition shown in Table 1. The component solution was filtered through a filter having a size of 0.2 μm to prepare a photoresist material.

In Table 1, each component is as follows.・ Organic solvents: PGMEA (propylene glycol monomethyl ether acetate) CyH (cyclohexanone) PGME (propylene glycol monomethyl ether) DAA (diacetone alcohol)

・ Acid generator: PAG1 ~ 3 (refer to the following structural formula) [Chem. 89]

・ Quenching agents 1, 2 (refer to the following structural formula) [Chemical 90]

(2) EUV exposure evaluation Each photoresist material prepared in Examples 1 to 11 and Comparative Example 1 was spin-coated with a silicon-containing spin-coated hard mask SHB-A940 manufactured by Shin-Etsu Chemical Industry Co., Ltd. having a film thickness of 20 nm. On a Si substrate (content of silicon: 43% by mass), a hot plate was used for pre-baking at 105 ° C. for 60 seconds to obtain a photoresist film having a thickness of 60 nm. On it, exposure was performed using an EUV scanning exposure machine NXE3300 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a hole pattern on the wafer having a pitch of 46 nm and a deviation of + 20% deviation) made by ASML Corporation, and exposed, and Using a hot plate, PEB was performed at a temperature described in Table 1 for 60 seconds, and development was performed with a 2.38% by mass TMAH aqueous solution for 30 seconds to form a hole pattern having a size of 23 nm. The length measurement SEM (CG5000) manufactured by Hitachi Advanced Technology Co., Ltd. was used to measure the exposure when the hole size was formed at 23 nm, which was defined as the sensitivity, and the size of 50 holes at this time was measured to obtain the size variation (CDU, 3σ). The results are shown in Table 1.

【Table 1】

From the results in Table 1, it can be seen that the photoresist material of the present invention containing a polymer containing a repeating unit represented by formula (a1) or (a2) has high sensitivity and good CDU.

no

Claims (10)

A photoresist material comprising a polymer containing a repeating unit represented by the following formula (a1-1) or (a2-1); In the formula, R ^A is a hydrogen atom or a methyl group; X ¹ is a single bond or an ester group; Rf ¹ to Rf ⁴ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or Trifluoromethyl; Rf ¹ and Rf ² may be combined to form a carbonyl group; R ¹ to R ⁵ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, and a straight chain , Branched or cyclic alkenyl with 2 to 12 carbons, straight chain, branched or cyclic alkynyl with 2 to 12 carbons, aryl with 6 to 20 carbons, 7 to 12 carbons Aralkyl groups, or aryloxyalkyl groups having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted with hydroxyl, carboxyl, halogen atoms, pendant oxygen, cyano, amido, Nitro, sultone, fluorenyl, or sulfonium-containing groups, a part of the methylene groups constituting these groups may also be substituted with ether, ester, carbonyl, carbonate, or sulfonate groups; and, R ¹ and R ² may be bonded and form a ring with the sulfur atom to which they are bonded; R ⁶ is a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms, a halogen atom other than iodine, Hydroxyl, linear, branched or cyclic carbon number 1 ~ An alkoxy group of 4 or a linear, branched or cyclic alkoxycarbonyl group of 2 to 5 carbons; m is an integer of 1 to 4; n is an integer of 0 to 3. For example, the photoresist material in the scope of patent application 1 contains an organic solvent. For example, the photoresist material in the first or second scope of the patent application, wherein the polymer further contains a repeating unit represented by the following formula (b1) or (b2); In the formula, R ^{A is} each independently a hydrogen atom or a methyl group; Y ¹ is a single bond, a phenylene group or a naphthyl group, or a carbon number of 1 to 12 containing at least one selected from an ester group and a lactone ring. A linking group; Y ² is a single bond or an ester group; R ¹¹ and R ¹² are each independently an acid labile group; R ¹³ is a halogen atom, a trifluoromethyl group, a cyano group, a linear, branched, or cyclic group Alkyl or alkoxy having 1 to 6 carbons, or straight, branched, or cyclic fluorenyl, alkoxy, or alkoxycarbonyl having 2 to 7 carbons; R ¹⁴ is a single bond, or A linear or branched alkylene group having 1 to 6 carbon atoms, and a part of its carbon atom may be substituted with an ether group or an ester group; p is 1 or 2; q is an integer of 0 to 4. For example, the photoresist material in the third patent application range is a chemically amplified positive photoresist material that further contains a dissolution inhibitor. For example, the photoresist material in the first or second patent application range, wherein the polymer does not contain an acid-labile group. For example, the photoresist material in the scope of patent application No. 5 is a chemically amplified negative photoresist material that further contains a crosslinking agent. For example, the photoresist material in the scope of patent application No. 1 or 2 further contains a surfactant. A pattern forming method includes the following steps: coating a photoresist material according to any one of claims 1 to 7 on a substrate, and performing a heat treatment to form a photoresist film; and using high energy rays to form the photoresist film Performing exposure; and developing the exposed photoresist film using a developing solution. For example, the pattern forming method according to item 8 of the application, wherein the high-energy rays are an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm. For example, the pattern forming method of the eighth patent application range, wherein the high-energy rays are electron beams or extreme ultraviolet rays having a wavelength of 3 to 15 nm.